This invention relates to marine steering systems and, in particular, to marine hydraulic steering systems for steering outboard motors which can tilt relative to the stern of a marine craft.
Marine steering systems have been developed for hydraulically steering outboard motors, but which permit tilting upwards of the outboard motors when the motors are not in use. Such steering systems conventionally included a steering wheel with an associated hydraulic pump and hydraulic lines connecting the pump to a steering assembly adjacent to the outboard motor. Such a system is disclosed, for example, in U.S. Pat. No. 5,997,370 to Fetchko et al. and in earlier U.S. Pat. No. 5,092,801 to McBeth. A system for steering twin outboard motors is disclosed in U.S. Pat. No. 6,406,340 to Fetchko et al.
Typically the systems include a pivot plate or pivot member which is pivotally connected to the tiller of an outboard motor. A pair of support arms or support brackets extend outwardly from the tilt tube of the motor. The piston rod of a hydraulic actuator is mounted on the support arms. The actuator has actuator arms extending outwardly from the cylinder thereof which are pivotally connected to the pivot member for pivoting about an axis parallel to the piston rod. The pivotal connection typically includes cylindrical passageways in the actuator arms and the pivot plate and separate pins extending through the cylindrical passageways which are retained by bolts.
In these earlier systems the actuator arms are typically formed in one piece with the barrel of the hydraulic cylinder. The cylinder has separate end glands connected to the barrel which slidably and sealingly receive the piston rod so that the piston rod reciprocates through the end glands.
This arrangement requires separate bolts or pins for connecting the hydraulic actuator to the pivot plate. Typically this requires two bolts, two washers and two pins. The pins are usually made of a high-strength material with high wear resistance in order to withstand the loads encountered.